Patents by Inventor Nien-Hui Kung

Nien-Hui Kung has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 7940596
    Abstract: A switching regulator includes a low-side switch having a body diode. During the low-side switch is on, a zero-current sense circuit monitors the inductor current of the switching regulator and triggers a signal to turn off the low-side switch when the inductor current falls down to a zero-current threshold, to prevent reverse inductor current from the output terminal of the switching regulator. A body-diode turn-on time controller monitors the turn-on time of the body diode and adjusts the zero-current threshold according thereto, and the turn-on time of the body diode can be reduced to an optimal interval subsequently. The self-adjustable zero-current threshold is adaptive according to the application conditions, such as the inductor size, input voltage and output voltage of the switching regulator.
    Type: Grant
    Filed: November 3, 2009
    Date of Patent: May 10, 2011
    Assignee: Richtek Technology Corp.
    Inventors: Kwan-Jen Chu, Nien-Hui Kung, Tzu-Huan Chiu, Chien-Ping Lu
  • Publication number: 20110095624
    Abstract: The present invention discloses a single wire transmission interface comprising: a signal detection circuit detecting level switchings of a transmission signal from a single wire, and generating an enable signal and a decoded signal corresponding to the transmission signal, the level switchings including first switchings from a first level to a second level and second switchings from the second level to the first level, wherein the enable signal starts according to one first switching of the transmission signal, and stops when no first switching occur in a predetermined period after one second switching of the transmission signal, and wherein rising edges (or falling edges) of the decoded signal correspond to the first switchings of the transmission signal; a counter, under enablement by the enable signal, counting a number of the rising edges (or the rising edges) of the decoded signal or the first switchings of the transmission signal, and generating a count; a single short pulse generator generating a shor
    Type: Application
    Filed: October 23, 2009
    Publication date: April 28, 2011
    Inventors: NIEN-HUI KUNG, KWAN-JEN CHU
  • Publication number: 20110080142
    Abstract: A charger circuit comprising: a charging path coupled between an input voltage and a battery; a power switch on the charging path; a switch control circuit controlling the power switch; a timer counting a charging period; and a low current control circuit issuing a signal to the switch control circuit to control the power switch such that a charging current is maintained to be a predetermined low current when the timer counts to a predetermined maximum charging period.
    Type: Application
    Filed: October 6, 2009
    Publication date: April 7, 2011
    Inventors: Nien-Hui Kung, Kwan-Jen Chu
  • Patent number: 7906939
    Abstract: A soft-stop circuit and method are provided for a voltage regulator which converts a battery voltage to an output voltage according to a feedback voltage derived from the output voltage and a reference voltage, to control the voltage regulator to enter a soft-stop state when the battery voltage is lower than a threshold level, and in which state, and the output voltage is controlled to decrease so as for the battery voltage to have a slower decreasing speed and in turn a longer battery lifetime.
    Type: Grant
    Filed: February 26, 2008
    Date of Patent: March 15, 2011
    Assignee: Richtek Technology Corp.
    Inventors: Nien-Hui Kung, Kwan-Jen Chu
  • Publication number: 20110043162
    Abstract: A charger for a portable device includes a USB detector connected to a data pin to detect the effective resistance on the data pin before a USB transceiver is enabled, to identify USB or adapter plug in and control a charging current for a battery accordingly.
    Type: Application
    Filed: August 16, 2010
    Publication date: February 24, 2011
    Applicant: RICHTEK TECHNOLOGY CORP.
    Inventors: LI-WEI LEE, NIEN-HUI KUNG, KWAN-JEN CHU, YING-HSIN HSING
  • Patent number: 7876000
    Abstract: The present invention provides a power path control circuit comprising: an input node for receiving an external power; a first power transistor electrically connected between the input node and a first node, for controlling power supplied from the input node to the first node; a second power transistor electrically connected between the first node and a battery, for controlling power supplied from the battery to the first node; an error amplifier including an output electrically connected with a gate of the second power transistor, a first input terminal electrically connected with the first node, and a second input terminal electrically connected with the battery, wherein a voltage difference is allocated between the two input terminals.
    Type: Grant
    Filed: March 24, 2009
    Date of Patent: January 25, 2011
    Assignee: Richtek Technology Corporation
    Inventors: Tzu-Huan Chiu, Kwan-Jen Chu, Nien-Hui Kung
  • Publication number: 20110012565
    Abstract: A charging circuit with an application system thereof provides an error amplifier to control a transistor switch for controlling the charging power source to charges the battery. When the voltage difference between the power source and load terminals of the transistor switch drops along with the transistor switch being turned on, the output voltage of the error amplifier changes as well to increase the turning-on resistance of the transistor switch such that the voltage difference between the power source and load terminals is capable of maintaining at a value above a certain reference level for avoiding the unstable state resulting from the charging circuit being turned on and off frequently.
    Type: Application
    Filed: December 7, 2009
    Publication date: January 20, 2011
    Applicant: Richteck Technology Corp.
    Inventors: Li-Wei LEE, Nien-Hui KUNG, Kwan-Jen CHU, Hsuan-Kai WANG
  • Publication number: 20110006728
    Abstract: A hybrid battery charger includes a control circuit and a power stage. The control circuit includes an error amplifier to generate a first error signal and a second error signal according to an output voltage and an output current of the hybrid battery charger, a linear controller to generate a first control signal according to the first error signal, a PWM controller to generate a second control signal and a third control signal according to the second error signal, and according to a mode signal, a multiplexer to select the first control signal for the power stage to operate the hybrid battery charger in a linear mode, or the second and third control signals for the power stage to operate the hybrid battery charger in a switching mode.
    Type: Application
    Filed: July 7, 2010
    Publication date: January 13, 2011
    Applicant: RICHTEK TECHNOLOGY CORP.
    Inventors: NIEN-HUI KUNG, KWAN-JEN CHU
  • Patent number: 7847516
    Abstract: A circuit and method for detecting absent battery condition in a linear charger apply a detecting signal onto an output terminal of the charger and monitor the output terminal to receive a detected signal. The capacitance at the output terminal is significantly different between the presence and absence of a battery connected to the output terminal, and it is thus available to determine from the detected signal, if no battery is connected to the output terminal.
    Type: Grant
    Filed: April 8, 2008
    Date of Patent: December 7, 2010
    Assignee: Richtek Technology Corp.
    Inventors: Nien-Hui Kung, Kwan-Jen Chu
  • Publication number: 20100231047
    Abstract: A power safety system includes a first MOS, a second MOS, a switch and a body controller. The first MOS is connected between a power input and a power output. The second MOSFET is connected between the power output and a charging output. The switch has an end connected to the body of the first MOS, and the opposite end switched between the source and the drain of the first MOS. A body controller controls the switch according to the voltage at the power input and the voltage at the power output, to connect the body of the first MOS to the source or the drain of the first MOS. By switching the switch, the first MOS will have a parasitic diode effective to prevent a reverse current from the power output to the power input.
    Type: Application
    Filed: March 9, 2010
    Publication date: September 16, 2010
    Applicant: RICHTEK TECHNOLOGY CORP.
    Inventors: LI-WEI LEE, NIEN-HUI KUNG, KWAN-JEN CHU, CHUN-TSUNG CHEN
  • Patent number: 7714556
    Abstract: A quick response switching regulator comprises a power stage having a pair of high-side switch and low-side switch and an inductor connected together by a switching node, a feedback circuit for producing a feedback signal, and a control circuit producing control signals with reference to the feedback signal to control the pair of high-side switch and low-side switch. The feedback circuit is connected to the switching node to shorten the feedback path and speed up the response. The control circuit further monitors the current flowing through the inductor to keep the low-side switch off before the peak of the inductor current becomes higher than a value.
    Type: Grant
    Filed: August 29, 2007
    Date of Patent: May 11, 2010
    Assignee: Richtek Technology Corp.
    Inventors: Kwan-Jen Chu, Tzu-Huan Chiu, Nien-Hui Kung, Chien-Ping Lu
  • Publication number: 20100072915
    Abstract: The present invention discloses a boost driver circuit which converts an input voltage to an output voltage and supplies it to a load, the boost driver circuit comprising: a power transistor electrically connected with a node between the input voltage and the output voltage; a pulse width modulation driver circuit for controlling the operation of the power transistor; an output node electrically connected with the output voltage; a feedback node electrically connected with the load; a low voltage transistor electrically connected with the feedback node; and a clamp and fast discharge circuit electrically connected with the feedback node for discharging the feedback node when the voltage at the feedback node is higher than a predetermined voltage.
    Type: Application
    Filed: April 1, 2009
    Publication date: March 25, 2010
    Inventors: Kwan-Jen Chu, Nien-Hui Kung, Tzu-Huan Chiu, Chien-Ping Lu
  • Publication number: 20100066312
    Abstract: The present invention discloses an overvoltage protection (OVP) circuit for use in a charger circuit system, comprising: a power transistor electrically connected between a voltage supply and a battery; an OVP circuit which turns off the transistor when a voltage supply exceeds a threshold value; and a multiplexing circuit electrically connected between an output of the OVP circuit and the gate of the transistor. The present invention also discloses a charger circuit with an OVP function, comprising: a single power transistor electrically connected between a voltage supply and a battery; an OVP control circuit which turns off the power transistor when a voltage supply exceeds a threshold value; and a charger control circuit which controls the gate of the power transistor to determine a charge current to the battery when the voltage supply does not reach the threshold value.
    Type: Application
    Filed: March 10, 2009
    Publication date: March 18, 2010
    Inventors: Chien-Ping Lu, Nien-Hui Kung, Li-Wei Lee, Kwan-Jen Chu, Ying-Hsin Hsing, Chun-Tsung Chen
  • Publication number: 20100060233
    Abstract: A charger for a battery system detects the voltage level of a data pin of the battery system to determine whether an external power source plugged in to the battery system is a USB voltage source. When the external power source is a USB voltage source, the charger will provide power for a USB transceiver of the battery system or enable it.
    Type: Application
    Filed: September 2, 2009
    Publication date: March 11, 2010
    Inventors: Nien-Hui Kung, Chun-Tsung Chen
  • Publication number: 20100052629
    Abstract: A switching regulator includes a low-side switch having a body diode. During the low-side switch is on, a zero-current sense circuit monitors the inductor current of the switching regulator and triggers a signal to turn off the low-side switch when the inductor current falls down to a zero-current threshold, to prevent reverse inductor current from the output terminal of the switching regulator. A body-diode turn-on time controller monitors the turn-on time of the body diode and adjusts the zero-current threshold according thereto, and the turn-on time of the body diode can be reduced to an optimal interval subsequently. The self-adjustable zero-current threshold is adaptive according to the application conditions, such as the inductor size, input voltage and output voltage of the switching regulator.
    Type: Application
    Filed: November 3, 2009
    Publication date: March 4, 2010
    Inventors: Kwan-Jen Chu, Nien-Hui Kung, Tzu-Huan Chiu, Chien-Ping Lu
  • Patent number: 7652945
    Abstract: A switching regulator includes a low-side switch having a body diode. During the low-side switch is on, a zero-current sense circuit monitors the inductor current of the switching regulator and triggers a signal to turn off the low-side switch when the inductor current falls down to a zero-current threshold, to prevent reverse inductor current from the output terminal of the switching regulator. A body-diode turn-on time controller monitors the turn-on time of the body diode and adjusts the zero-current threshold according thereto, and the turn-on time of the body diode can be reduced to an optimal interval subsequently. The self-adjustable zero-current threshold is adaptive according to the application conditions, such as the inductor size, input voltage and output voltage of the switching regulator.
    Type: Grant
    Filed: March 31, 2008
    Date of Patent: January 26, 2010
    Assignee: Richtek Technology Corp.
    Inventors: Kwan-Jen Chu, Nien-Hui Kung, Tzu-Huan Chiu, Chien-Ping Lu
  • Publication number: 20090315527
    Abstract: For output current detection of a voltage regulator, the currents in a high-side transistor and a low-side transistor of the voltage regulator are sensed and summarized to a summed current to flow through a setting resistor. The voltage variation on the setting resistor is monitored to provide a feedback signal for feedback control in the voltage regulator. This detection scheme removes the current sensing resistor from the charging current path of the voltage regulator to prevent efficiency loss on it, and is much less sensitive to noise interference because greater voltage variation is available by using a greater setting resistor.
    Type: Application
    Filed: June 18, 2009
    Publication date: December 24, 2009
    Inventors: Nien-Hui Kung, Kwan-Jen Chu
  • Publication number: 20090261654
    Abstract: The present invention provides a power path control circuit comprising: an input node for receiving an external power; a first power transistor electrically connected between the input node and a first node, for controlling power supplied from the input node to the first node; a second power transistor electrically connected between the first node and a battery, for controlling power supplied from the battery to the first node; an error amplifier including an output electrically connected with a gate of the second power transistor, a first input terminal electrically connected with the first node, and a second input terminal electrically connected with the battery, wherein a voltage difference is allocated between the two input terminals.
    Type: Application
    Filed: March 24, 2009
    Publication date: October 22, 2009
    Inventors: Tzu-Huan Chiu, Kwan-Jen Chu, Nien-Hui Kung
  • Patent number: 7605571
    Abstract: The present invention discloses a switching regulator, which comprises: a first and a second transistors electrically connected with each other; a pulse width modulation control circuit for turning ON and OFF the first transistor and turning ON the second transistor; and a current source control circuit for controlling the second transistor so that the second transistor becomes a current source, wherein the second transistor has only two states: ON and low current, and wherein when the first transistor is ON, the second transistor is in the low current state; and when the first transistor is OFF, the second transistor is ON or in the low current state.
    Type: Grant
    Filed: August 17, 2007
    Date of Patent: October 20, 2009
    Assignee: Richtek Technology Corporation
    Inventors: Nien-Hui Kung, Kwan-Jen Chu
  • Publication number: 20090237035
    Abstract: A circuit and method for detecting absent battery condition in a linear charger apply a detecting signal onto an output terminal of the charger and monitor the output terminal to receive a detected signal. The capacitance at the output terminal is significantly different between the presence and absence of a battery connected to the output terminal, and it is thus available to determine from the detected signal, if no battery is connected to the output terminal.
    Type: Application
    Filed: April 8, 2008
    Publication date: September 24, 2009
    Inventors: Nien-Hui Kung, Kwan-Jen Chu